Laminated sheet pulp container and method of forming same



L. M. WILEY Feb. 26, 1946;

LAMINATED SHEET PULP CONTAINER AND METHOD OF FORMING SAME 7 Sheets-Sheet1 Filed Dec.

7 INVENTOR.

L. M. WILEY Feb. 26, 1946.

LAMINATED SHEET PULP CONTAINER AND METHOD OF FORMING SAME Filed DC.

7 Sheets-Sheet 2 INVENTOR. 7 LEE /7. l V/Lfh BY I Feb. 26, 1946.

L. M. WILEY LAMINATED SHEET PULP CONTAINER AND METHOD OF FORMING SAME 7Sheets-Sheet 5 Filed Dec. 3, 1942 l O y O l/wmro/z 45s mew/5r WWW Feb.26,1946. 7 1... M. WILEY 2,395,703

LAMINATED SHEET PULP CONTAINER AND METHOD 0F FORMING SAME Filed Dec. 3,1942 7 Sheets-Sheet 4 ff'fln gi nu &\\\\\\\ 1.. M. WILEY 2,395,703LAMINATED SHEET PULP CONTAINER AND METHOD OF FORMING SAME Feb. 25, 1946.

' 7 Sheetls-Sheet 5 Filed Dec. 3, 1942 uwm/ra/a, LEE M. WILEY Feb. 26,1946. M. WILEY LAMINATED SHEET PULP 2,395,703 0F FORMING SAME L.' M.WILEY Feb. 26; 194 6 LAMINATED SHEET PULP CONTAINER AND METHOD OFFORMING SAME 7 Sheets-Sheet '7.

Filed Dec; 3, 1942 Patented eb. .26, 194.6

I I 2,395,103- I j LAMINATED snna'r PULP CONTAINER METHOD OF FORMINGSAME Lee M. Wiley, Marlon, Ind assignor of one-third to Julian Wiley '1.Lett and one-third to Reeley B.

I Applicatlon'Dec embei- 1942, Serlal'No. 467,715 1 Claim. (c'l. 154-2)invention relates to a deep drawn seamless container formed primarily ofsheet pulp stock.

The present invention also is directed to the means for and method oflaminating such stock to produce a composite, laminated sheet prior] toformation therefrom oi the aforesaid container.

'Ihelaminated-sheet comprises the stock which is first passed throughimpregnating tanks, andthen through a wringer structure to form amoistened lmpreg'nat ed loop which is then fed to blanking dies to formblanlm. These blanks are then precreased anddrawn through tubular dieextensions by plungers that subsequently eject the partially formedarticle into a receiver mold wherein the container side wall precreasedstock is consolidated and distributed bythe plunger dated May 16, 1944;No. 2,348,272, dated May 9, 1944; No. 2,296,889, dated Sept. 29, 1942;No. 2,354,564, dated July 25, 1944; and allowed application Serial No.444,671, now Patent No. 7 3 2, dated June 5, 1945.

Since these patents are readily available for a detailed disclosure ofcomplete article formation,

and since thersum hereinbefore briefly summarizes said disclosuresynofurther reference to form 'an article that approximates final form.

The receiver molds are turret mounted and suceessively presented inindexed turret rotation to successive pressure stations and a finaldischarge station. Here the articles are sultably transferred to aconveyor for transportation to and through a heater.

This heater evaporates the remaining moisture not mechanically extrudedfrom the article. These articles are then pressure formed and .inoversize relation and then shrunk to size in a second heater thatoperates at a temperature high enough to cause dispersion anddistribution of the residual impregnate or size. Final pressure formingand decorating then may be elTected if desired.

An alternate method or processing is for the conveyor supported, turretmold ejected articles to pass through a unitary two stage heater, in thefirst stage (of longer duration) being subjected to drying and in thesecond stage (shorter duration) being subjected to furtherdrying but ata higher temperature sulficient to thermally condition the articlecarried impregnate or size, so that it can be consolidated in afinalpressure formation. 5

The latter may occur in a turret type mechanism, there being includedbetween the receiv- I ing molds of the same and'the conveyor beyond theheater, a suitable stripper.

The turret die consolidated and formed article may then be printed,decorated or the like, as desired, and finally ejected.

Illustrative ofapparatus and methods for practicing parts of the presentinvention reference may be had to the following copending patents:

No. 2,337,581, dated Dec. 28, 1943; N0.'2,348,871,

thereto is believed necessary if it be distinctly understood that thepresent disclosure is directed to laminated sheet formation forlaminated article formation. I

The subsequent disclosure is confined, to minimize descriptive matteronly.- However, it, is amplified by a disclosure of the article, orrather parts and sections thereof when including the laminated sheetpulp stock of this invention.

The chief object of thisinvention is to provide a laminated pulp sheetincluding outer layers or plies of sheet pulp and an intermediate layeror ply of plastic for reenforcement purposes, for hermetic sealingpurposes, and for non-tacky handling of the subsequent-laminated sheetin the several processes and apparatuses summarized hereinbefore andalso illustrated and described in said patents.

. The chief feature of the present invention condesired, of tackyplastic, water repellent and/or thermal and/or pressure setting incharacter.

Other objects and features of this invention will be set forth morefully hereinafter.

The full nature of the invention will be understood from theaccompanying drawings and the following description and claim:

.In the drawings,

Fig. 1 is a diagrammatic elevation outline of the prelaminatingformation of a laminated paper board pulp sheet including the inclusionof a sheet of plastic for laminating purposes.

Fig. 2 is a similar view of a modified formof the invention andrepresents plastic lamination inclusion when the plastic is in liquidform.

Fig. 3 is a similar view of a further. modified form of the inventionand when the plastic lamination is initially in powder form.

Fig. 4 is a top plan viewof an article including the laminated sheet andprior to final consolidation steps disclosed in the copendingapplications.

Fig. 5 is a similar view on an enlarged scale of a small sectionthereof.

Fig. 6 is a view similar to Fig. 5 andwith the parts of the article infinal wall consolidated repulp sheets I and it when presented thereto.

lotion. This occurs at or immediately prior to the sheets Fig. 'l 'is avertical sectional view taken on line passing through the booster andsqueezing rolls 1-1 of Fig. 4 and in the direction oi the arrows and ona scale approximately four times Fig. 4 scale. which may, forillustration purposes, be considered substantially full size.

Fig. 8A is a longitudinal sectional view of one apparatus illustratingthe blanking, pre-creasing,

creasing and initial formation of the article.

Fig. BB is a similar view of the dehydrator through which the articlepasses.

Fig. 8C is a similar view of an. intermediate forming press and a secondoven through which the article passes.

ing die shown in Fig. 8A.

Fig. 10 is a face view of the stationary precreas- 45 adjacent tank II.

In passing through these rolls, or a similar pressure roll set ahead ofsame, the three sheets are caused to adhere together. The plastic layerbeing water repellant thus prevents water passage through the laminatedsheet; Since the plastic ply is flexible, it will conform with the twoouterplies of the sheet to whatever deformation the laminated sheet isthereafter subjected.

Reference will now be had to Fig. 2. In this disclosure theplasticintermediate ply initially .is

Fig. 9 is a face view of the movable precreas-' ing corrugated andtubular die shown in Fig. 8A.

Figs. lla, 11b and 110 are sectional views showing successive relativepositions of the movable pre-creasing die and stationary pre-creasingdie, immediately prior to pre-creasing, intermediate pre-creasing andfinal pre-creasing of the blank.

Fig. 12 is a side elevation of a modified form of apparatus to which theconveyor shown in Fig. 8A may connect and which may replace theapparatus shown in Figs. 8B and 8C and is distinguished by an oven withsuperposed communicatin: chambers of dehydrating and presettingcharacter anda turret type final former.

In each of the Figs. 1 to 3, i0 indicates a roll support and il a secondroll support, the former supporting a roll i2 of prime pulp sheeting(bleached or unbleached) and the latter supporting a similar roll i3.From the same are drawn the sheets ll and i5 respectively.

Following suitable plastic inclusion therebetween. as hereinafter morefully set forth, the resuiting laminated sheet it passes into animpregnating tank I! below an impregnating solution immersed roll 18suitably suspended in the tank t as at IS. The sheet then passes Tbelowroll 20 similarly suspended as at 2i and thence passes upwardly betweenwringer rolls 22.

The impregnating solution in the tank I1 is of the desired character,but is intended primarily for surface treatment of the finished article.

The sheet i6 extends upwardly from the wringer rolls 22 and passes overan elevated support roll 23 supported as at 24. A gravity reof liquidcharacter, being contained'in a tank 50, the-same being automatically ormanually suppliedwith the'liquid and the temperature of which'may beautomatically or manually controlled if. necessary.

In said tank 50 is a doctor roll 5i for transferring the liquid to theapplicationr'oll 52 over which passes the sheet i4. Sheet l5 passes overroll 53 and engagzs the plastic covered lower face of sheet i4. Uppersqueeze roll 54 cooperates with lower roll 53 to cause adherence of thenow plastic inner layer to both liner plies. The resultant is alaminated pulp sheet similar to that previously described.

In Fig. 3 a third method of plastic lamination application isillustrated. Herein the plastic is in powder form. The two sheets 14 andi5 pass between booster rolls B0 and then into tank 6| through inlet610. It then passes below roll 62 in the tank and out through outlet6117. This tank contains vapor for softening the two sheets.

Steam supply lines, etc., 63- are provided.

The softened sheets then pass between squeeze rolls 64 and surplussoftening material, if condensed, is squeezed out and runs back on thesheets and into the tank. The sheets, after passing between the squeezerolls 6!, separate and the lower sheet (ply I5) passes over approach Iroller' 65 and platen '66. The upper sheet passes tained light roll 25,with shaft 26 seated in slots 21 of support 24 overlies and bears onthe sheet The sheet i6 leaving roll 23-45 forms a loop or festoon 28 andthe other end thereof passes over roll 29 of the block diagrammedforming machine 30, see Figs. 1 to '3. Herein one or more impregnatingtanks H and associated mechanism' may be utilized as desired orrequired.

Reference will now be had to Fig. 1 herein.

Between rolls i2 and i3 and upon a roll support 40 there is supported a'roll ll of plastic in sheet form. A separating sheet of non-adheringmaterial such as holland cloth may be included when necessary, but isstripped as the roll is stripped leavingonly the plastic sheet 42. Theseparating strip disclosure is omitted for clarity as well as any rewindstructure therefor if utilized.

The water repellant, normally non-tacky flexible sheet 42 is thensubjected to a suitable solvent spray 43 obtained by passing the sheetbetween oppositely directed solvent discharging spray nozzles 44. Thissolvent tempers the plastic sheet 42 surfaces so same will adhere to theover 'overhead roller 61 and 68.

Between the two sheets is a supply container 69 containing powderedplastic. The discharge therefrom may be regulated in the throat Ill.

The powder P drops or is forced under pressure onto the upper face ofsheet l5, while on the platen 66. A gauge ii, of adjustable character,determines the thickness of the powder -layer. This gauge may be ofscraper type.

A pair of squeeze roll l2 and 13 are positioned adjacent the dischargeend of the platen 66. Sheet 14 passing over roll 68 passes under roll12. Sheet l 5, covered with powdered plastic to the desired depth,passes directly from the platen to roller 13. The two sheets with theincluded powdered plastic are then consolidated in their passage throughrolls 12-13 into a laminated sheet similar to each of the aforesaidsheets.

As previously stated, each of the laminated sheets i6 then passesbetween boosterand squeeze rolls 45 and then through tank i1 and wringer22-22 forming loop 28 prior to introduction to the forming machine 30.

Reference will now :be had to Figs. 4 to '7 inclusive. The compositesheet as stated is initially blanked, see left-hand portion of Fig 8A.and the blanks precreased, see same portion of Figs. 8A, 11a, 11b andthen drawn through a die, see Figs. 8A and 10, and seated in-a femalemold, see Fig. 8A, and pressure molded to approximate form (see centralportion of Fig. 8A).

Figs. 83 and 8C disclose respectively a dehyasearos drator and a formingpress and second oven. The movable precreasing die is illustrated inFig. 9 as well as Fig. 8A. Fig. 12 illustrates an alternative compositedehydrating and tempering oven and another form of final finishingpress, same being of the turret type.

Fig. 8A corresponds to Fig. 1 of Patent 2,348,272.

Fig. 83 corresponds to Fig. 2 thereof and Fig. 86' corresponds to Fig. 3thereof.

Figs. 9 audio correspond to Figs. 9 and- 10 of Patent No. 2,337,581.

Figs. 11a, 11b and lie correspond respectively to Figs. 12, 13 and 14.of the aforesaid last mentioned patent.

Fig. 12 corresponds to Fig. 1 of Patent No.- 2,377,392.

In Figs. 4 and 7, 80 indicates the bottom of the article initiallyformed, 8| the sidewall portion immediately contiguous thereto, 82indicates the initially pleated portion and 83 the upper fully pleatedportion. Fig. illustrates the upper fully pleated portion 83 priortofull consolidation.

Each pleat in cross section is substantially U- shaped with inturned armportions, see Fig. 5.

The successive pleats are reversed in position and are continuations ofeach other. When the pleats are finally consolidated, see Fig. 6, theinterior and exterior surfaces of the container or article are ofcontinuous wood pulp type. The plastic layer is therebetween and alsopleated. This obviously constitutes a stifi ribbed reenforcement for thecontainer sidewall. No external or internal ribbing or creases appearin. the finished product. The pulp sheets due to impregnation have thedesired finish.

The intermediate layer of plastic or ribbed reenforcement between thepulp sheets, so far as the side wall is concerned, adds considerablestrength to the molded container over one of pellency, heat resistanceand the like and by surthe same wall thickness, but made of a singlepulp sheet, or a plurality of pulp sheets. The present invention forms ahomogeneous wall between the two fibre walls so that hermetically sealedpackaging can be accomplished where pulp d only might fail.

It will also be apparent that by laminating in i any oi the mannersillustrated and described practically any thermoplastic material can beused for the laminated board due to the fact so either or both may betreated for water reface treatment only. Difierent colored sheets alsomay be employed with the present invention, so that either interior orexterior or both can 'be of the desired color or colors.

The critical feature of the present invention is the formation of amultiply sheet with an included plastic bond between adjacent pulpsheets and coextensive therewith, the plastic being homogeneously unitedto the confronting surfaces of the plastic-bonded sheets. v

Desirable characteristics are strengthening of the article, possiblehermetical sealing of the article, subsequent formation, withoutdimculties enumerated, of multi-plyblanks into containers.

While the invention has been illustrated and described in great detailin the drawings and foregoing description, the same is to be consideredas illustrative and not restrictive in character.

The several modifications described herein, as well as others which willreadily suggest themselves to persons skilled in this art, all areconsidered to be within the broad scope of the invention, referencebeing had to'the appended claim.

The invention claimed is;

A method of forming a deep drawn. seamless, laminated wall container ofsubstantially uniform wall thickness in transverse section and with aninner surface forming pulp layer, an outer surface forming pulp layerand an intermediate imperforate plastic layer therebetween comprisinginitially assembling two water and size absorbing pulp plies with awater repellant, 'teinperature and pressure settable bonding plasticlayer therebetween and coextensive therewith. consolidating bypressurethe plies and layer into 'a unitary laminated sheetimpregnatingthe pulp piles of the sheet with moisture. the'impregnation being withor without size as desired, wringingthe sheet to the desired moisturecontent for subsequent working of the sheet in blank form such asinitially precreasing the'blank and then forming side wall flutes orpleats in the blank in registration with the creasing. compressing.consolidating and distributingthe fluted material to form an articlewith an imbedded imperforate plastic reinforcement of concentriccircumferential and radial type in the wall. and of approximately finalform, pressure consolidating the 31".

ticle to nearly finalform, subjecting the article between the sheets tosuccessive heatingsfor drying and setting purposes. and finally pressurefinishing the article to final container form.

